This project would establish a national Xenopus Resource Center at the Marine Biological Laboratory (MBL) in Woods Hole, MA. White Papers submitted to NIH by the Xenopus research community describe the urgent need for a center to house animal stocks and to disseminate new technology. Several laboratories, primarily those who are key personnel on this proposal, have defined the husbandry, health and housing conditions needed to develop a major stock center. The MBL is an ideal place for such a center because it is acknowledged as a premier site for biological research; it has a long association with the Xenopus research community and, as part of a Regenerative Medicine initiative, will fund the construction of a new Xenopus Center if funds are obtained for Center operation in 2009. This resubmission has four aims. The first entails setting up the facility in year 1 and generating critical animal lines (wildtype, inbred, transgenic and mutant). In aim 2, covering years 2-5, the scope of the facility will be expanded, to provide a spectrum of animal lines recognized as a high priority by the research community. In addition, transgenic and genetic core facilities will be established as part of the new Center to allow new lines to be generated, and for researchers to visit the facility to learn technologies associated with these areas. In the third aim, we focus on the role of the proposed Center in disseminating new technology This would include a series of minicourses to be offered at the Center, to be taught by experts in particular areas (e.g. husbandry, transgenesis, advanced imaging, preparation of egg extracts, bioinformatics). The final aim focuses on animal husbandry, include setting up protocols for enhanced husbandry and health surveillance, and disseminating these to the research community. Experiments are proposed to optimize husbandry to improve fertility of females and shorten the time to sexual maturity. Some key changes in this resubmission are: 1) an increased emphasis on X. laevis stocks (and concomitant reduction of X. tropicalis stocks) in order to better serve community needs; 2) development of a clearer leadership plan; 3) reduction in the complexity of aims (e.g. reducing stock number in the Center; removing forward genetics core); and 4) clarification of health and disease outbreak issues.